As Lady of Fungi, Zuggtmoy as originally presented resembled a huge puffball fungus on top of four elephantine legs. A toadstool shaped head with squashed and vague humanoid-like features resided atop her body. She could extrude pseudopods from her bloated body and squash opponents. Canonically, Zuggtmoy can also appear as a feeble old crone or a ravishingly beautiful human female. When the Temple of Elemental Evil computer game was released in 2003, Zuggtmoy was given an updated image makeover. Instead of the almost comical puffball-mushroom look of T1-4, she was given a more fearsome appearance: resembling a blue-skinned demonic female with long sharp claws and whose lower body consists of strands of fungoid matter. Recent publications, such as Fiendish Codex I: Hordes of the Abyss and Dragon, have Zuggtmoy retaining this more impressive appearance (see picture at right), whereas her original fungoid form has become an aspect.

Zuggtmoy is an ally of Iggwilv and Iuz, and has also been romantically linked to the latter. She shares her layer of the Abyss with the demon lord Juiblex. She has been seen working with the demon lord Haagenti, the Lord of Alchemy, as well.

Zuggtmoy is served by her lieutenant, Yibiyru, the Rancid Lady of Bitter Bile. Her most notorious hero-priest was the druid Xhagevoxhab, who once ruled a vast territory in the Underdark over 600 years ago.

Zuggtmoy is served by elemental rukarazylls and vathugu demons, aas well as various fungal creatures.

Zuggtmoy rules the 222nd layer of the Abyss, officially called Shedaklah, although according to her creator Gary Gygax, it is called Mycorji. She shares this layer with Juiblex, the Faceless Lord. Also called the Slime Pits, Shedaklah is a duo-layer: its surface is overran by fungi and plant creatures while its underground corollary is infested with oozes and slimes. Zuggtmoy claims the surface realm whereas Juiblex is confined to below ground. As a result of her setbacks in the "T" modules, Juiblex has managed to lay claim to parts of the surface realm. It was with the efforts of Zuggtmoy's lieutenant, Yibiyru, the Rancid Lady of Bitter Bile, that Juiblex didn't conquer all of Shedaklah.

Zuggtmoy rules from the center of the layer in a palace that consists of two dozens or so gigantic mushrooms, each connected to each other by shelf-fungi, and each four miles tall. Numerous chambers and corridors has been carved within the mushrooms; it is said not even Zuggtmoy herself knows the full extent of the palace.

In the T modules, Zuggtmoy is revealed to be a competitor and enemy of Lolth. She built the Temple of Elemental Evil along with her ally, Iuz. The forces of good launched a campaign against her, trapping her within the temple's confines. In the current World of Greyhawk Timeline, Zuggtmoy is presumed released from the Temple by Robilar.

In Gary Gygax's Gord the Rogue novels, Zuggtmoy is one of the so-called "Monarchs of Demonium." She also has a vile artifact called the Cauldron of Corruption, a small kettle-like object covered with bumps, knobs and other weird protrusions. Upon command, it can grow into a huge cauldron and shoots out jets and sprays of flesh-eating and poisonous slimes and spores.